I'd record at 44.1/16bit as any noise floor performance benefits gained by recording at 24 bit, will be underneath the ambient noise from bleed due to it being a live performance on stage. And it'll be slightly less taxing on the computer, which is always a nice thing when recording live.
A standard audio CD is 44.1/16bit, and holds approx 700MB of data, so as Davey said, about 10MB/min is about the norm-- obviously you'll want to have a bit of margin here, so estimate about 3GB to have spare.
A side note: a less full hard drive performs better than a full one, as does a properly defragmented one-- if the heads have to keep skipping around to get to the unused space, you're more likely to get an error, rather than if it can all be held in the same location on the disk. I'd advise doing a de-frag of your disk, and also you'll want to kill any antivirus, backup software etc. as that'll also make it more likely to drop out of record, or give you an error.